The present invention relates to a packaging container adapted to be kept germ-free after having been filled with sterilized food and drink and also to a method for filling said packaging container with sterilized food and drink in a germ-free manner.
Recently, germ-free filling of food and drink has rapidly come into wide use to meet a market demand for long period preservation of food or drink without deterioration of its quality.
Particularly for drink, such germ-free filling technique has been adopted in practice for many years and presentation for a period in order of three months and an effort and an attempt have been made to develop an improved technique which will be effective generally for processed foodstuffs.
One of such method for germ-free packaging of food- stuffs is disclosed by Japanese Patent Publication No. 1980-3218, which utilizes a molded container to perform filling of food stuffs under a germ-free condition and more specifically, comprises steps of molding the container so as to establish first of all said germ-free condition inside the container, sterilizing also the exterior of said molded container, transferring said molded container into a germ-free chamber in which a top of said molded container is then opened, filling said molded container with food or drink through the opened top and then sealing said molded container.
According to this prior art, the respective steps such as those of container top opening and food or drink filling may be carried out in the germ-free atmosphere to provide products suitable for long term preservation.
However, such germ-free filling and packaging system of prior art has been found to be disadvantageous in that the respective steps such as those of sterilizing, opening and sealing the container are designed for a particular molded container and, in consequence, the system could not accommodate any variation in design factors, for example, a configuration of the molded container being handled only within a limited range.
In other words, the respective steps are usually required by the germ-free filling and packaging system, for example, the steps of container transferring, container opening, content filling and sealing container are designed for a particular configuration of the container to be handled by this system and, therefore, it has inconveniently been necessary for such germ-free filling and packaging system that said system must be substantially redesigned each time it is desired, using the same system to handle a group of containers of a different configuration. In addition, such germ-free filling and packaging system should be provided in the respective steps with additional technical means in order that this system is previously designed so as to accommodate containers of various types.
Accordingly, in order to accommodate molded containers of various types, the germ-free filling and packaging system of prior art would be bulky and of a correspondingly increased cost. It is impossible to make the system compact and thereby to reduce its installation space thereof.
Furthermore, shutdown of type system is required each time the type of the container, for example, the configuration thereof is changed, so that the continuous operation is precluded and, in a consequence, it becomes difficult for the desired germ-free condition to be maintained.
In view of a fact that a market demand has increased for wider variety of goods, a demand for an improved germ-free filling and packaging technique adapted to accommodate the containers of various types with ease has correspondingly increased.